Field of the Invention
The present invention relates to an image processing apparatus and an image processing method, and in particular, to an image processing apparatus and an image processing method that can be effectively used for dividing an image of a single frame into a plurality of images and processing the plurality of divided images.
Description of the Related Art
Conventionally, regarding image processing performed on a high-resolution image such as a 4000×2000 (4K2K) image and an 8000×4000 (8K4K) image, there have been proposed an architecture for dividing an image of a single frame into a plurality of full high definition (FHD) images and processing the plurality of divided FHD images in parallel, and a method for transmitting images divided in advance. A pixel adjacent to a pixel at an end of a divided image corresponds to a pixel at an end of a divided image adjacent to this divided image. Therefore, when filter processing is performed on the end of the divided image, this processing is performed with reference to a part of pixels at the end of the divided image adjacent to this divided image. In the following description, a term “margin pixel” will be used to call, among pixels at an end of a divided image, a pixel that is referred to when the filter processing is performed on an end of a divided image adjacent to this divided image, as necessary.
There are techniques discussed in Japanese Patent Application Laid-Open Nos. 2000-312311 and 2009-010613 as techniques for performing the filter processing on the divided image in this manner.
According to the technique discussed in Japanese Patent Application Laid-Open No. 2000-312311, after dividing an image of a single frame acquired from a television camera into a plurality of images, an image processing apparatus generates an image in which a margin pixel is added to each of all of the divided images as a pixel at an end of a divided image adjacent to this divided image that is referred to during the filter processing. Then, by referring to the margin pixel added to the divided image, the image processing apparatus processes a pixel at an end of this divided image.
According to the technique discussed in Japanese Patent Application Laid-Open No. 2009-010613, an image processing apparatus receives an image of a single frame, divides the received image into a plurality of images to read out the divided images, performs signal processing on the divided images, and then outputs the divided images. When reading out the divided images, the image processing apparatus scans two divided images vertically adjacent to each other by scanning lines in the upper divided image from the top to the bottom while scanning lines in the lower divided image from the bottom to the top.
However, in a case where the image processing apparatus is configured to include a filter processing circuit immediately after an input for an image analysis or the like, and the divided images are input in parallel, the technique discussed in Japanese Patent Application Laid-Open No. 2000-312311 requires another divided image to be stored in a frame buffer during processing of one divided image. Alternatively, this technique requires a line buffer for the margin pixel to be prepared for each of the divided images to process the divided images in parallel. Therefore, the technique involves a problem of an increase in a memory cost.
Further, according to the technique discussed in Japanese Patent Application Laid-Open No. 2009-010613, scanning directions (readout directions) in the divided images that are referred to by each other are set to reverse directions of each other so that upper and lower margin pixels are referred to by the image processing apparatus at similar timings. In a commonly-used image scanning method, pixels are scanned from the left to the right with respect to a horizontal direction, and pixels are scanned from the top to the bottom with respect to a vertical direction. Therefore, this technique involves a problem of requiring a special transmission/reception apparatus when the image is transmitted.